对WPF中MeasureOverride 和ArrangeOverride 浅理解

以前对MeasureOverride 和ArrangeOverride十分费解，看到了这篇博文茅塞顿开~

 public class CustomControl1 : Panel
     {
         /// <summary>
         /// 先测量需要多大尺寸，做个申报准备
         /// </summary>
         /// <param name="constraint">限定的尺寸，比如，规定了width和height</param>
         /// <returns></returns>
         protected override Size MeasureOverride(Size constraint)
         {
             //定义预期的宽度和高度
             double height = , width = ;
             UIElement element;
             //遍历每个元素，计算所需的总尺寸
             for (int i = ; i < Children.Count; i++)
             {
                 element = Children[i];
                 //按照限定的尺寸测量一下自己，拿镜子找着自己
                 element.Measure(constraint);
                 if (height < element.DesiredSize.Height)
                     height = element.DesiredSize.Height;
                 width += element.DesiredSize.Width;
             }
             //申报，我需要这个尺寸
             return new Size(width, height);
         }

         /// <summary>
         /// 排列每个元素
         /// </summary>
         /// <param name="arrangeBounds">测量的尺寸</param>
         /// <returns></returns>
         protected override Size ArrangeOverride(Size arrangeBounds)
         {
             double currentX = ;
             UIElement element;
             for (int i = ; i < Children.Count; i++)
             {
                 element = Children[i];
                 //排列每个元素
                 Children[i].Arrange(new Rect(currentX, , element.DesiredSize.Width, element.DesiredSize.Height));
                 currentX += element.DesiredSize.Width;
             }
             return arrangeBounds;
         }
     }

 <local:CustomControl1  Width="" Background="Gray" HorizontalAlignment="Right" Margin="0,20,151,280">
             <Rectangle Width="" Height="" Fill="Red" Margin="10,10,0,0" />
             <Rectangle Width="" Height="" Fill="Yellow" Margin="10,10,0,0" />
             <Rectangle Width="" Height="" Fill="Green" Margin="10,10,0,0" />
         </local:CustomControl1>

本文来自xiaokang088的博客，原文地址:http://www.cnblogs.com/xiaokang088/archive/2011/01/08/1930952.html